Fused Filament Fabrication also known by Stratasys's trade names of FUSED DEPOSITION MODELING or FDM involves extruding plastic filaments using a nozzle which is heated to melt the plastic filaments. Various problems are associated with this process. One of the most significant is the problem of how to melt and then extrude high temperature plastic filaments (such as, but certainly not limited to polyetherimide or polyphenylsulfone or particle loaded plastics), in a compact form while preventing the high temperature from spreading into undesirable areas.
Excess mass and surface area in the heated section imparts more heat via convection to the 3D printed part than is desirable. This results in the printed part warping due to thermal gradients in the part. Previously users of extruders have insulated the nozzle from the surface using various materials but problems remain. For example previous designs which have used heater cartridges installed in tubes have increased the radiating potential of the nozzle contributing to excessive undesirable printed part heating.
Low melting point metals, glass and ceramic composites, and thermoplastics exist in three primary states determined by the temperature of the material: solid, liquid, and ‘gummy’ Solid plastic and other materials can be forced into the extruder and liquid plastic is expelled. A key requirement for an extruder is the minimize blockage due to ‘gummy’ plastic lodging between the solid and liquid states. Existing extruders have used Polyetheretherketone (PEEK) and Polytetrafluoroethylene (PTFE) sleeves in order to make the flow path smoother but without addressing the core problem of allowing material to exist in the ‘gummy’ state. One design, the E3D does use a thin walled stainless steel tube. Yet problems remain.
Another problem relates to the need for extruders to be disassembled by trained service people in order to service the nozzle and flow path.
Yet another problem relates to the limited material choice which is restricted by filaments.
A further problem relates to the limitation in heat thus restricting the ability to print metals and metal alloys.
Thus, various problems associated with fused filament fabrication exist. What is needed are methods, apparatuses, and systems for addressing these problems.